HID: core: clamp report_size in s32ton() to avoid undefined shift
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: HID: core: clamp report_size in s32ton() to avoid undefined shift s32ton() shifts by n-1 where n is the field's report_size, a value that comes directly from a HID device. The HID parser bounds report_size only to <= 256, so a broken HID device can supply a report descriptor with a wide field that triggers shift exponents up to 256 on a 32-bit type when an output report is built via hid_output_field() or hid_set_field(). Commit ec61b41918587 ("HID: core: fix shift-out-of-bounds in hid_report_raw_event") added the same n > 32 clamp to the function snto32(), but s32ton() was never given the same fix as I guess syzbot hadn't figured out how to fuzz a device the same way. Fix this up by just clamping the max value of n, just like snto32() does.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 2.6.20 and later | 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0.1, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 2.6.20 and later Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0.1, 7.1 Patch available CNA
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0.1, 7.1
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2026-31624
- 2026-10-03 Alias added: GHSA-7r46-pv4v-9gxj
- 2026-11-06 CISA SSVC decision points changed
References
Patch 6
- https://git.kernel.org/stable/c/932ae5309e53561197aa7d1606c7cf63af10e24f
- https://git.kernel.org/stable/c/58386f00af710922cafb0fb69211497beddfaa95
- https://git.kernel.org/stable/c/8a8333237f1f5caab8d4c3d2c2e7578c4263a97f
- https://git.kernel.org/stable/c/ea363a34086ddb4231adc581a7f36c39ec154bfc
- https://git.kernel.org/stable/c/97014719bb8fccb1ffcbbc299e84b1f11b114195
- https://git.kernel.org/stable/c/69c02ffde6ed4d535fa4e693a9e572729cad3d0d
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Sources
- CVE-2026-31624 · CVE Program
- CVE-2026-31624 · NVD
- FIRST EPSS
- GHSA-7r46-pv4v-9gxj · GitHub Advisory Database · CC BY 4.0
- CVE-2026-31624 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences